named 100% utilization

we are having a problem with bind that has been happening for about a week. one of named's threads goes to 100% and then named stops responding to any dns requests.  I have logging turned on and dont see anything out of the ordinary.  It's not crashing. Any recommendations on where to start

bind_dlz and views and samba

As I understand it bind_dlz does not support multiple views, I have to following scenario and am trying to figure out how to configure it: * Internal (192.168.10.0/24) o resolve internal domain xyz.com o resolve internal samba domain xyz.lab o resolve single address xyz.3cx.us